This disclosure relates to ferritic alloys, and specifically to development of low activation bainitic and martensitic stainless steels.
Ferritic alloys are required for structural usage in the development of commercial fusion systems, where the residual fuel and wastes will themselves have negligible residual radioactivity. For purposes of this disclosure, "low activation" shall be defined as a radiation level below 1 Ci/m.sup.3 after waste disposal and burial for one hundred years.
Low activation characteristics have not been vital in the development of structural materials for use with nuclear fission reactors, since the high levels of long term radioactivity that persist in the spent fuel generated by a fission system far overshadows the amount of radioactivity in the surrounding structure. Most research and development with respect to long term radioactive levels has been directed to the fuel components, rather than to the machine structure.
This invention arose from a study designed to develop low activation bainitic and martensitic stainless steels for structural applications in the vicinity of nuclear fusion reaction processes. In the case of nuclear fusion reactors, the fusion reaction itself does not create any radioactive fuel components which require subsequent disposal. However, the bombardment of the surrounding machine structure by sub-elemental particles could result in production of isotopes which might have persistent radioactive levels throughout projected waste disposal storage times.